The latest article in our OSNews OS contest: Learn about MorphOS, the heir to the Amiga legacy. This article chronicles its bumpy history, its still-compelling features, and the current state of MorphOS development.

>"Well, OS4 is just OS3.9 on an AmigaONE", or "Windows XP is just Win98 with skins."

While I can't comment on MOS, but I certainly can assure you guys AmigaOS4 is not OS3.x with some gimmicks (skins etc.). I, however, doubt, that MOS delivers anything beyond AmigaOS4, maybe in a different way (if you want to count Ambient and MUI4 + some api extension, and I don't know what it adds to the (amigaos)kernel below).
AmigaOS4 has changed dramatically (new kernel, new intution, new graphics, usb/tcp/>4GB files, etc) - well, mostly under the hood, though. But the comment "MOS extends AmigaOS" can only be true for it's base, the AmigaOS33.1.